I have long maintained (and occasionally demonstrated), to the consternation of the women in my life, that you can dance pretty funkily to Bach. David McVicar seems to feel the same way about Handel. The numerous hip- rolling setpieces sewn into his ENO staging of Agrippina certainly serve to keep the audience going through the inevitable longueurs of its four hours, but they are also in danger of sending it up, of diminishing the 23-year-old composer's remarkable achievement.

Jiving drunk in a nightclub to Handel's first great work for the theatre? Snorting cocaine to milk some cheap laughs from up-tempo coloratura? Repeated use of the F-word, starkly up there in the surtitles, as noun and verb as well as multiple expletive? These are dangerous tactics from opera's perennial enfant terrible, but McVicar has always been a director ready to take risks. Updating ancient Rome to designer-dress, recasting its feuding patricians as preening celebrities far from keen to get out of here - these are risks of the highest order. But risks worth taking.

McVicar's irreverent assault on the piece, first seen in Brussels in 2000, exceeds even his Glyndebourne Giulio Cesare in its remorseless Bollywood-style excesses. Whenever an aria sags, not least because of its repetitive text, he has those involved trip a two-step. Or croon a piano-bar lament. Or swing a golf club. There is much fondling, groping and crotch-contact, between all available sexual permutations. Ambitious for her son Nerone to inherit the throne, Agrippina alternates between slinky black negligee and celebrity shades above Fashion Week power-dressing. Nerone himself is a spiky-haired punk rocker in urgent need of an Asbo.

It's not often a mezzo in a 'trouser role', in this case the excellent Christine Rice as Nerone, is required to remove those trousers for a quick flash. Lucy Crowe's beguiling Poppaea, the most exciting discovery in this universally well-sung production, is rendered the more so by her frequent stripteases. Her lover Ottone, Scottish counter-tenor Reno Troilus in another impressive debut, is dressed throughout as a panto Buttons.

As the emperor Claudio, house favourite Brindley Sherratt at last gets a role worthy of his considerable stage heft and vocal resonance. The show is supposedly a star vehicle for that fine mezzo Sarah Connolly; at first uncertain in the title role, then overconfident, she is most impressive in her later, stiller moments, when McVicar at last reins in his sight gags as her devious plans go awry. For the first-night audience, however, Connolly's Agrippina was cumulatively upstaged by Crowe's ringing, seductive Poppaea.

With mincing attendants surplus to requirements, and senior soldiers obliged to jive in uniform, McVicar can seem almost desperate for lazy laughs. But his reading of the piece as a straightforward satire on the corrupting elements of power is clinched at the end with a vision of the future, as Poppaea deserts Ottone to flirt with Nerone as he ascends the throne. Without the brisk pace set by Daniel Reuss in the pit, this could well seem an even longer evening than it already is. But McVicar's vision of female power-lust - of the Hillarys and Cheries of this world, its Indiras and Evitas - will no doubt delight the Coliseum's chattering classes.

Two remarkable young pianists passed through town last week, each bringing a fresh vitality to a familiar warhorse. At Cadogan Hall, the Royal Philharmonic's handsome home in Chelsea, Freddy Kempf drew the audience to its feet with his effortless virtuosity in Tchaikovsky's first concerto, while Lars Vogt sparkled through a South Bank Schumann with the Philharmonia. On adjacent evenings, they almost seemed to vie for supremacy in the subtle contrasts of their shading, their flits from soft to robust touch; already well established, each will mature into a master. Both orchestras were also at the top of their games, the RPO bringing an especial sparkle to Stravinsky's Pulcinella under Leonard Slatkin, and Christoph von Dohnanyi wringing wonderful warmth from the Philharmonia in Schoenberg and Brahms. One wonders how much the South Bank orchestras will miss the intimacy of the Queen Elizabeth Hall when the refurbished Festival Hall reopens in June.